Aplicación de ejemplo de uso de Pickers y Dialogs del Curso de desarrollo de aplicaciones Android.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="tech.alvarez.ejemplopickerdialogs.MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:onClick="abrirPickerHora"
        android:text="@string/hora" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:onClick="abrirPickerFecha"
        android:text="@string/fecha" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:onClick="abrirMensaje"
        android:text="@string/dialogo_mensaje" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:onClick="abrirItems"
        android:text="@string/dialogo_items" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:onClick="abrirSeleccion"
        android:text="@string/dialogo_seleccion" />


</LinearLayout>

arrays.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="colores">
        <item>Rojo</item>
        <item>Verde</item>
        <item>Morado</item>
    </string-array>
    <string-array name="lenguajes">
        <item>Java</item>
        <item>C++</item>
        <item>Swift</item>
    </string-array>
</resources>

build.gradle

// build.gradle del módulo
apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.0"

    defaultConfig {
        applicationId "tech.alvarez.ejemplopickerdialogs"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.0.0'
}

MainActivity.java

package tech.alvarez.ejemplopickerdialogs;

import android.app.DatePickerDialog;
import android.app.Dialog;
import android.app.TimePickerDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.text.format.DateFormat;
import android.view.View;
import android.widget.DatePicker;
import android.widget.TimePicker;
import android.widget.Toast;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void abrirPickerHora(View view) {
        TimePickerFragment timePickerFragment = new TimePickerFragment();
        timePickerFragment.show(getSupportFragmentManager(), "timePicker");
    }

    public void abrirPickerFecha(View view) {
        DatePickerFragment datePickerFragment = new DatePickerFragment();
        datePickerFragment.show(getSupportFragmentManager(), "datePicker");
    }

    public void abrirMensaje(View view) {
        MiDialogFragment miDialogFragment = new MiDialogFragment();
        miDialogFragment.show(getSupportFragmentManager(), "memsaje");
    }

    public void abrirItems(View view) {
        MiItemsDialogFragment miItemsDialogFragment = new MiItemsDialogFragment();
        miItemsDialogFragment.show(getSupportFragmentManager(), "items");
    }

    public void abrirSeleccion(View view) {
        MiSelectorDialogFragment miSelectorDialogFragment = new MiSelectorDialogFragment();
        miSelectorDialogFragment.show(getSupportFragmentManager(), "multi");
    }


    public static class TimePickerFragment extends DialogFragment implements TimePickerDialog.OnTimeSetListener {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final Calendar fechaActual = Calendar.getInstance();
            int hora = fechaActual.get(Calendar.HOUR_OF_DAY);
            int minuto = fechaActual.get(Calendar.MINUTE);
            return new TimePickerDialog(getActivity(), this, hora, minuto, DateFormat.is24HourFormat(getActivity()));
        }

        public void onTimeSet(TimePicker view, int hora, int minuto) {
            // cuando se selecciona la hora
            Toast.makeText(getActivity(), "Se selecciono " + hora + ":" + minuto, Toast.LENGTH_SHORT).show();
        }
    }


    public static class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final Calendar fechaActual = Calendar.getInstance();
            int anio = fechaActual.get(Calendar.YEAR);
            int mes = fechaActual.get(Calendar.MONTH);
            int dia = fechaActual.get(Calendar.DAY_OF_MONTH);
            return new DatePickerDialog(getActivity(), this, anio, mes, dia);
        }

        public void onDateSet(DatePicker view, int anio, int mes, int dia) {
            // cuando se selecciona la fecha

            Toast.makeText(getActivity(), "Fecha: " + dia + "/" + mes + "/" + anio, Toast.LENGTH_LONG).show();
        }
    }


    public static class MiDialogFragment extends DialogFragment {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            builder.setTitle(R.string.titulo);
            builder.setMessage(R.string.mensaje);
            builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    Toast.makeText(getActivity(), "Acepto!!", Toast.LENGTH_LONG).show();
                }
            });
            builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    Toast.makeText(getActivity(), "Cancelo!!", Toast.LENGTH_LONG).show();
                }
            });

            builder.setNeutralButton(R.string.neutral, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    Toast.makeText(getActivity(), "nEUTRO!!", Toast.LENGTH_LONG).show();
                }
            });
            return builder.create();
        }
    }


    public static class MiItemsDialogFragment extends DialogFragment {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            builder.setTitle(R.string.titulo);
            builder.setItems(R.array.colores, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    Toast.makeText(getActivity(), "Item " + i, Toast.LENGTH_LONG).show();
                }
            });

            return builder.create();
        }
    }


    public static class MiSelectorDialogFragment extends DialogFragment {
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            builder.setTitle(R.string.titulo);
            builder.setMultiChoiceItems(R.array.lenguajes, null, new DialogInterface.OnMultiChoiceClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i, boolean b) {
                    // cuando se selecciona item posición i con estado b
                    Toast.makeText(getActivity(), "Item " + i + " > " + b, Toast.LENGTH_LONG).show();
                }
            });
            builder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            });
            builder.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            });


            return builder.create();
        }
    }

}

strings.xml

<resources>
    <string name="app_name">EjemploPickerDialogs</string>
    <string name="hora">Hora</string>
    <string name="fecha">Fecha</string>
    <string name="titulo">Título</string>
    <string name="mensaje">Un mensaje</string>
    <string name="neutral">Neutro</string>
    <string name="dialogo_mensaje">Diálogo Mensaje</string>
    <string name="dialogo_items">Diálogo Items</string>
    <string name="dialogo_seleccion">Diálogo Selección</string>
</resources>